Abnormal intestinal permeability and microbiota in patients with autoimmune hepatitis.

BACKGROUND Autoimmune hepatitis (AIH) is a chronic, progressive, and immunologically mediated inflammatory liver disorder. The etiology of AIH still remains unknown. The aim of this study was to investigate the changes in intestinal permeability, bacterial translocation, and intestinal microbiome in patients with AIH and to evaluate the correlations of those changes with the stages of the disease. METHODS 24 patients with autoimmune hepatitis and 8 healthy volunteers were recruited for this study. We assessed (1) the integrity of tight junctions within the gut by immunohistochemical analysis of zona occludens-1 and occludin expression in duodenal biopsy specimens; (2) changes in the enteric microbiome by 16S rDNA quantitative PCR; and (3) the presence of bacterial translocation by the level of lipopolysaccharide (LPS) using ELISA. RESULTS Increased intestinal permeability, derangement of the microbiome and bacterial translocation occurred in AIH, which correlated with the severity of the disease. CONCLUSIONS Autoimmune hepatitis is associated with leaky gut and intestinal microbiome dysbiosis. The impaired intestinal barrier may play an important role in the pathogenesis of AIH.